Fragment energy correlation measurements for the proton induced fission of 226Ra

Abstract

The yield, average total fragment kinetic energy and width of the total fragment kinetic energy distribution have been determined as functions of fragment mass from two parameter fragment energy correlation experiments for the proton-induced fission of 226Ra. Results were obtained for proton energies Ep = 9, 11 and 13 MeV. The average total fragment kinetic energy is found to decrease slowly with increasing compound nucleus excitation energy. The observed rate of decrease is generally largest for fragment pairs in which one fragment is near doubly magic, i.e. for heavy fragment mass ∼ 132 a.m.u. Increase in relative yield of the symmetric peak of the mass distribution with increasing excitation energy is once again observed. These and other observations are interpreted in terms of the previously proposed two-component hypothesis together with molecular model considerations including the assumption that the number of quasiparticle excitations at scission is determined by the excitation energy at the saddle point.